LONDON, United Kingdom (AFP) – UK police said on Thursday they had arrested a 17-year-old boy over a cyber attack on the body that runs London’s public transport networks.

Transport for London (TfL) said some customer names and contact details had been compromised in the attack which was discovered on September 1.

Some refund data that could include bank account details, may also have been accessed, it added.

“We have been working at pace to support Transport for London following a cyberattack on their network, and to identify the criminal actors responsible,” said Paul Foster, deputy director of the National Crime Agency’s cyber crime unit.

“Attacks on public infrastructure such as this can be hugely disruptive and lead to severe consequences for local communities and national systems,” he added.

The incident follows a cyberattack in June that led to major disruption at London hospitals.

The attack on a firm supplying lab services particularly hit blood transfusions, and hundreds of appointments and operations were cancelled.

The attack affected some of the UK’s biggest hospitals — King’s College Hospital and Guy’s and St Thomas’ in the centre of the British capital.

The NCA said the teenager suspected of the TfL incident was arrested in central England on September 5.

He was questioned and released on bail.